In general, when construction machinery is started begins and an operation thereof begins, an engine is driven with about 2000 RPM to 2500 RPM, and when the operation is completed, that is, there is no continuous operation after a predetermined time from a time at which the operation is completed, a vehicle control unit performs an idle control of decreasing the RPM of the engine to about 1200 RPM.
Further, when a separate front operation, steering operation, or manipulation for driving is not generated for a predetermined time in the state where the idle control is performed, the vehicle control unit also determines this situation as the idle state to perform an auto idle control of decreasing the RPM of the engine to about 800 RPM so that the engine is driven with a minimum RPM.
As described above, the construction machinery is controlled so that the control is performed so as to change an operation RPM to an idle RPM according to existence of the operation state, and the control is performed so as to change an idle RPM to an auto idle RPM according to existence of the idle state to drive the engine.
In the meantime, recently, as becoming an age of high oil price, demands for improving fuel efficiency of construction equipment have been gradually on the rise.
Accordingly, development of a technology for improving an effect of fuel efficiency by decreasing an RPM of the engine when the idle state is continued even in the auto idle state, as well as the existence of the operation state and the idle state, has been urgently demanded.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.